The little-known "United Patriot National Front" -- which the Southern Poverty Law Center claims is linked to violent white nationalists (for what that's worth) -- cancelled their rally on Sunday, but hundreds of left-wing activists showed up for a counter-protest anyway.

“Domingo, a former U.S. Army Infantryman, wanted to use improvised explosive devices against innocent civilians and he selected components that would make the bombs even more deadly to the victims he targeted,” said Assistant Attorney General Demers. “His arrest today mitigates the threat he posed to others in the Los Angeles community. I want to thank the agents, analysts, and prosecutors who are responsible for this investigation and arrest.”

In online posts and in conversations with an FBI source, Domingo expressed support for violent jihad, a desire to seek retribution for attacks against Muslims, and a willingness to become a martyr, according to the affidavit. After considering various attacks – including targeting Jews, churches, and police officers – Domingo decided to detonate an IED at a rally scheduled to take place in Long Beach this past weekend. As part of the plot, Domingo asked his confederate – who actually was cooperating with the FBI as part of the investigation – to find a bomb-maker, and Domingo last week purchased several hundred nails to be used as shrapnel inside the IED.

"Domingo said he specifically bought three-inch nails because they would be long enough to penetrate the human body and puncture internal organs," U.S. Attorney Nicola Hanna said.

“This investigation successfully disrupted a very real threat posed by a trained combat soldier who repeatedly stated he wanted to cause the maximum number of casualties,” said Hanna. “Protecting Americans from terror attacks is the number one priority of the Justice Department, and anyone who plots to use a weapon of mass destruction will be held to account.”

“The individual charged in this case wanted to carry out a mass casualty attack with explosive devices, and he moved very quickly from talking about violence to mobilizing to commit such an attack,” said Assistant Director Michael McGarrity of the FBI’s Counterterrorism Division. “This case should remind the public of the need to be vigilant and notify law enforcement if you see suspicious behavior.”

“I can tell you, unequivocally, that this partnership, coupled with our ability to be nimble, ultimately resulted in dozens of innocent lives being saved in Southern California,” said Los Angeles Police Chief Michel R. Moore.

Hanna said Domingo had murderous designs on a variety of groups, including Christians, Jews, police, the military, his next-door neighbor and/or crowds of people.

"At times, Mr. Domingo said he wanted to kill Jews as they walked to synagogue. At other times, he said he wanted to kill and target police officers, attack a military facility or attack crowds at the Santa Monica Pier," the U.S. attorney said.

According to the criminal complaint, Domingo posted an online video professing his Muslim faith on March 2, and the next day made another posting in which he said, “America needs another vegas event.

"There were mosque shootings in new Zealand," Domingo posted to a private group online after the shootings, according to federal prosecutors. "[T]here must be retribution."

Domingo allegedly added: "I feel like I should make a christians life miserable tomorrow for our fallen bros n sis in [N]ew Zealand...maybe a jews life...they shed our blood...no Muslim should have to experience this, a message needs to be sent."

In response to the postings, an FBI “confidential human source” (CHS) began an online conversation that resulted in a series of in-person meetings with Domingo. During the first meeting, on March 18, “Domingo discussed with the CHS different targets for an attack, including Jews, police officers, churches, and a military facility,” according to the affidavit.

During subsequent meetings outlined in the affidavit, Domingo continued to express his desire to commit a terrorist act, at points contemplating a drive-by shooting with a modified AK-47-style rifle he owned, and at other points considering the use of an IED. During an April 3 meeting, Domingo allegedly expressed support for ISIS and said “if ISIS ‘came here,’ he would swear allegiance to ISIS,” according to the complaint.

The plan to target the rally came into shape during an April 19 meeting, when Domingo arrived to a meeting with the CHS armed with an AK-47-style rifle “to show you that I’m serious,” according to the complaint. During that meeting, Domingo referenced the Boston Marathon bombing and asked the CHS to find a person to construct an IED that he said could cause 50 casualties.

When asked if he thought he would get caught, Domingo allegedly offered a chilling response: "Martyrdom, bro," Domingo said, according to the affidavit.

Officers seized three rifles and ammunition during a search of Domingo's home and vehicle, authorities said.

When Domingo converted to Islam, his family considered it a positive thing.

“I thought maybe my brother finally found some sort of guidance in this world,” his younger brother James Domingo said. “Like anybody else, I don’t want to assume a thing when someone is going into a new religion.”

When a dozen FBI agents showed up at his Reseda home on Friday to arrest his brother, James Domingo said he was shocked. I hope this dies down eventually and hopefully my brother will be found innocent of this,” he told theLos Angeles Daily News.

Domingo is facing a statutory maximum sentence of 15 years in federal prison for "providing and attempting to provide material support to terrorists."